Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 7: Poster Magnetism I
MA 7.17: Poster
Montag, 9. März 2026, 09:30–12:30, P2
Miniaturized Multipoles for Ultrafast Electron Microscopy — •Johannes Schultz1, Max Herzog1, and Axel Lubk1,2 — 1IFF, IFW Dresden, Helmholtzstraße 20, 01069 Dresden — 2IFMP, TU Dresden, Haeckelstraße 3, 01069 Dresden
Ultrafast Electron Microscopy (UEM) is an emerging technique developed in the last decades. By combining the high spatial resolution of EMs with a temporal resolution down to fs, it provides insights into dynamic processes in the field of nanophotonics, magnetodynamics, and lattice motion among others. Most UEM setups use pumped electron sources, which provide the highest time resolution but suffer from a limited repetition rate (≈10 MHz), are expensive and technically complex and hence difficult to (retro)fit into EMs. We therefore propose an alternative technique based on easy-to-retrofit, miniaturized (for fast switching) magnetic multipoles chopping the beam to short pulses. They consist of planar copper electrodes with permalloy pole pieces on top (≈ 50 µm size), which are structured by lithography on a silicon wafer. The devices are supplied with radio-frequency electrical signals via a custom made holder compatible with standard ports of our EM (FEI Titan3), which allows for easy device integration into the central part (C2 aperture plane) of the condenser system. In the lower part of the EM, the beam is chopped by a small aperture (C3 aperture). Considering the magnification of the condenser system, the optical power of the devices (100 µrad deflection at 3 GHz and 300 keV electron energy) and the diameter of the chopping aperture (150 nm), a time resolution of ≈ 1 ps at repetition rates ≫ 10 MHz can be achieved.
Keywords: Transmission Electron Microscopy; Ultrafast